It has been known that the addition of Si-bonded hydrogen to an aliphatic multiple bond, often referred to as "hydrosilylization", can be promoted with platinum catalysts. For example, U.S. Pat. No. 3,798,252 to Nitzsche et al discloses the addition of Si-bonded hydrogen to aliphatic multiple bonds in the presence of a platinum catalyst which is obtained from the reaction of chloroplatinic acid and ketones.
Although U.S. Pat. No. 3,188,299 to Chalk teaches that platinum compositions containing a nitrogen ligand inhibit the addition of the Si-bonded hydrogen to an aliphatic multiple bond at room temperature, applicants have found that even though the platinum-containing catalysts of this invention contain basic nitrogen compounds, they are more effective and more reactive even at room temperature, i.e., they have shorter induction times than other platinum catalysts which promote the addition of Si-bonded hydrogen to an aliphatic multiple bond. Another important advantage of this invention is that less time is required between the initiation and termination of the hydrosilylization reaction, i.e., the reaction proceeds at a much faster rate with the platinum-containing compositions of this invention. Still another advantage of this invention is that lower concentrations of platinum and/or the platinum-containing compositions of this invention are required and they are more effective over a longer period of time. Furthermore, the platinum-containing catalysts of this invention do not promote polymerization of the initial reactants and the formation of undesired end products.
Therefore, it is an object of this invention to provide a platinum catalyst which will promote the addition of Si-bonded hydrogen to an aliphatic multiple bond. Another object of this invention is to provide a platinum catalyst which is more effective at room temperature. Another object of this invention is to provide a platinum catalyst which is more reactive at room temperature. Still another object of this invention is to provide a platinum catalyst which is more effective even at lower concentrations. A further object of this invention is to provide a platinum catalyst which is more effective over a longer period of time. A still further object of this invention is to provide a platinum catalyst which does not promote polymerization of the initial reactants and the formation of undesired end products.